The present invention relates generally to the field of internal combustion engines and in particular to an engine in which air intake and compression take place in the chambers of at least two piston-cylinder assemblies and combustion and exhaust take place in the chambers of a turbine assembly.
Rotary engines with pistons pivotally mounted on a rotating rotor have been in the engine art for some time. For example, U.S. Pat. No. 1,349,353 to Wilber discloses a rotary engine and a lever arm fixed thereon having a roller upon its end. At the same end of the motor and around a shaft is hung a cam having raised portions upon its surface, upon which the roller of the lever arm is made to bear. As the roller is moved over the cam, the hinged pistons are moved completely into the combustion chambers at the time the rollers reach the summit of the raised portions of the cams, and are permitted to move out again as the roller drops or moves off the raised portion of the cam. The roller upon the lever arm fixed to the shaft to which the piston is rigidly secured, moves up an inclined surface of the cam face thereby rocking the corresponding piston out of its recess.
Another example is U.S. Pat. No. 3,993,029 to Eiermann et al. which discloses a compound supercharged rotary piston engine device in which a rotary piston compressor is interposed between a pair of rotary piston engines to form a unit. A single shaft extends through the unit and has coaxial eccentrics for the engines and an eccentric displaced 180 degrees therefrom for the compressor. The compressor supplies primary combustion air to the engines and also supplies air thereto for after an burning uncombusted fuel entrained in the exhaust gases of the engines. The air supply from the compressor to the engines takes place in a set of passages in the walls which separate the compressor from the engines and the passages are under the control of the pistons of the device. Also see U.S. Pat. No. 1,048,308 to Hanley and U.S. Pat. No. 1,400,255 to Anderson.
Through the years other U.S. patents have been issued for improvements and changes to the original rotary engine concept.
For example, U.S. Pat. No. 5,531,197 to Lobb discloses a rotary internal combustion engine that includes a block having a generally elliptically shaped bore and a substantially round rotor adapted to rotate on a straight shaft in the bore of the block. The rotor is provided with a pair of substantially diametrically mounted rotor segments, the rotor being provided with a pair of recesses for receiving the rotor segments and the rotor segments being pivotally mounted to the rotor such that a portion of each rotor segment tends to be forced outwardly by centrifugal force upon the rotation of the rotor. The block is provided with a charging and a combustion space formed in the space between the elliptical shaped bore and the round rotor. The combustion chamber is enlarged by the outward movement of an outer segment pivotally mounted on the block. A pair of vanes between the rotor segments are mounted in slots on the rotor for the forming of a seal between the rotor and the inner surface of the bore of the block. The engine may be operated on any type of gaseous fuel. The narrowing of the space between the round rotor and elliptically shaped bore functions to compress the air/fuel mixture enclosed between the vane and the rotor segment. The engine provides two combustions per revolution. Larger engines may be constructed coupling any number of rotors and blocks either in line or side by side with the rotors coupled together. A variable displacement engine is provided by varying the size of the combustion chamber by limiting the outward movement of the outer segment.
Another example of an improved rotary internal combustion engine is shown is U.S. Pat. No. 4,843,821 to Paul et al. which discloses a compound rotary-reciprocal engine with multiple cylinders of a reciprocator component coupled to a positive displacement, rotary compressor-expander, with systems for coordinating the cycle timing of each cylinder with the timing of the rotary compress or expander and with systems enabling the efficient operation of the coupled components as a unitary engine in a wide range of operating conditions.
However, the above mentioned prior art references all suffer from significant drawbacks. Firstly, in the prior art references, and especially in Wilber, the engines rely on springs and mechanical means to open the variable blades and they do not make proper use of centrifugal force. Instead their design employs elaborate mechanisms to move the pistons outward. For example, Wilber relies on cams and rollers to move the pistons outward. Thus, they can not achieve high revolutions per minute (RPMs), which is an important limiting factor. Making proper use of centrifugal force is critical to achieving high RPMs and without high RPMs there can be no power output of significance.
Additionally, in Wilber as well as the other prior art engines, the blades have a “pocket” shape and generally cam shape, which limits the length of the power stroke, and as well as the RPMs. Additionally, the compression schemes. Furthermore, the above mentioned references do not compress the air which is used ion the combustion process in separate piston chambers which also limits the RPMs which they can achieve.
Accordingly there is a need for an engine which can employ a simple design that can both make proper use of centrifugal force and thus achieve high RPMs, as well as overcome the other drawbacks associated with the disclosed prior art engines.